1. Technical Field
The present invention generally relates to computer systems, and more particularly to a method and apparatus for disguising key click sounds made during password entry or entry of other sensitive information.
2. Description of the Related Art
A typical computer system has a keyboard input device, a visual display device, a processing unit containing memory and one or more processors, and various other system peripherals to provide input and output for the system. Many systems contain a speaker, either in the processing unit, the keyboard, or the display device, to provide audible feedback for various purposes such as error indications, keystroke echo clicking, and audio for entertainment and other purposes.
Many of today""s applications of computers are sensitive to misuse by other persons. Computers in the workplace tie individuals"" identities to user codes and passwords. Responsibility for information protected by passwords can be a liability for both employees and companies. In addition, applications of computers today sometimes directly involve money or monetary transactions. These transactions occur in the home as well as workplaces, due to the use of the Internet as a medium for sales and banking transactions.
Present point-of-sale systems follow generally the above description of a computer system, with the addition of a cash drawer and a receipt printer, among other peripherals. Such a system is directly sensitive to misuse, as knowledge of the password can provide access to the cash drawer.
Present systems to protect the integrity of a password on a computer system include devices and methods for visually disguising the password. The password is concealed during entry by replacing the normal display output of the text of the password with a non-revealing character (typically an asterisk), suppressing the display of text totally, generating random characters, or employing other means to visually disguise the password from unauthorized observation.
Unauthorized persons may also gain information from the sound of a password or other sensitive information as it is being typed on a keyboard. The most obvious example of this is the length of a password entry. An unauthorized person may simply count the number of keystrokes heard to learn the number of characters in the password.
Computer keyboards make mechanical noise, and some systems may generate audible key clicks by use of a keyboard echo apparatus or program means for generating key click sounds by speakers or other audio devices connected to the computer. These key click echo generators are typically used to provide feedback to the typist. These sounds can also provide information to an unauthorized user, which it is desirable to protect.
Similarly, Point-Of-Sale machines (POS) and Automated Teller Machines (ATM) require the use of passwords or Personal Identification Numbers (PIN) for access to accounts. These machines might also benefit from enhanced security if the sounds produced by the operation of their keypads were masked by generating sound while the keys are being pressed.
It is possible that sophisticated listening devices could be created that could use the variations present in key position to determine, after some analysis, a mapping of the keyboard sounds to the individual characters.
It would, therefore, be desirable to provide a method and apparatus for disguising the key click sounds of mechanical origin or those generated by a computer system. It would be further advantageous if a key click echo provided by a computer system could be randomized or varied in tone, volume, or spacing in such a way as to disguise the actual characters and number of characters which were typed by a user entering a password or other sensitive information.
The inventors are aware of no other invention that performs the desired function, and therefore have provided a novel use for novel methods and apparatus claimed herein.
It is therefore one object of the present invention to provide a method for disguising sounds created by operation of an input device during the input of sensitive information.
It is therefore another object of the present invention to provide a method for disguising key click sounds created by operation of a computer during the input of sensitive information.
It is another object of the present invention to provide a method for disguising key click sounds created by operation of a computer during the input of sensitive information by creating random variations in the key click patterns of a key click echo generator.
It is another object of the present invention to provide a masker capable of disguising input device sounds.
It is still another object of the present invention to provide a key click masker capable of disguising key click sounds.
It is yet another object of the present invention to provide a computer system having control means for causing an audio output device to mask key click sounds.
It is yet another object of the present invention to provide a computer program product for causing a computer system to control its audio output device to mask key click sounds.
The foregoing objects are achieved in a key click masker and method for masking key clicks. They also may be embodied in a computer system, or practiced on a general purpose computer by the execution of a program provided as a computer program product. The key click masker generally comprises a control means which may be embodied in a general purpose computer, a keypad or keyboard connected to the computer, and an audio generator, which may be a sound generator within the computer comprising a speaker and driver electronics. Said method may be embodied in a computer program, which may be embedded in the BIOS (Basic Input/Output System) of a general purpose computer, or may be provided as a device driver, other operating system program, or in an application program.
The above, as well as additional objectives, features, and advantages of the present invention, will become apparent in the following detailed written description.